A Y-profile steel bar or post (ie. fencing picket as used in agriculture) typically has a spine extending along a central longitudinal axis of the bar and three lateral arms (flanges/webs) that extend both longitudinally along and generally radially from the spine. Typically, one of the arms is longer than the other two and it is this arm that usually has openings or other types of retainers for retaining fencing members such as fencing wire.
Throughout this specification the longer arm will be referred to as the ‘long arm’ of the bar.
A well known Y-profile steel bar/post 1 is shown in FIG. 1 and has a long arm 2 having a tapered free end 5. Such a bar 1 is typically hot rolled using a two-high mill stand 6 (ie. having upper 7 and lower 8 rolls that meet together on a horizontal plane that form the Y-shape) of a rolling mill, as shown in FIG. 2.
Problems with, and disadvantages of, rolling a steel bar using a 2-high mill stand 6 include the following:                The long arm 2 of the bar 1 occasionally gets stuck in the upper roll 7 of the stand 6, thereby stopping production and causing damage to the roll mill. That is, when rolling the bar 1 the long arm 2 is very difficult to produce and often gets wedged in a groove 9 of the upper roll 7 and the bar 1 tends to wrap around the roll 7. This problem can be reduced by shortening the radial length of the long arm 2, or by heavily tapering the free end 5 of the long arm 2, but this profile greatly reduces the strength of the bar 1.        The bar section has poor tolerance and finish. In order to be able to roll the long arm 2, the final (roll pass) roll stand of the mill must have a ‘loose fit’ around the free end 5 of the long arm 2 so that the end 5 is less likely to be grabbed and wrapped around the roll 7. This means that dimensional tolerance is poor and that the finish of the bar 1 will be rougher.        There is premature roll (die) wear. There is a significant difference in diameter between a top of the groove 9 and a bottom of the groove 9 of the upper roll 7 through which the long arm 2 passes. As the roll 7 spins the difference in diameter equates to significant variations in surface speed. As the bar 1 passes through the rolls 7, 8 the difference in surface speed causes slippage of the rolls 7, 8 which causes them to wear very quickly.        Due to the roll configuration and geometry only certain profile shapes are possible. Due to the roll 7, 8 configuration, the free end 5 of the long arm 2 must either be tapered or of substantially uniform thickness along the radial length of the long arm 2—but never tapered in the direction of the free end 5 to the spine 10.        
All of these problems and disadvantages are currently managed by compromising either bar profile/strength, surface finish of the bar, or the efficiency of the whole profile rolling process.